Paul died in hospital on the same night in October 1968 that Peter witnessed him being attacked.

He never regained consciousness after suffering a fractured skull and died within four hours.

A police inquiry was launched at the time after bruises and burns were found on the boy, but Dearlove was never prosecuted.

That changed in 2015 when Peter Booth, incensed after seeing the photo on Facebook of his little brother sitting on Dearlove's knee, went to the police.

It led to the former ICI-worker being arrested at home in Great Yarmouth, Norfolk, and being questioned in Middlesbrough.

'He killed him and destroyed his memory': Paul's family's statement

'As has been heard in Court Paul Booth, our brother and son would have celebrated his 50th birthday this year.

'Thinking about this makes us sad, as Paul would have been a man, no doubt married and more than likely with children of his own. However, sadly Paul was not given the opportunity to live his life due to the cruel and wicked actions of David Dearlove.

'This was a man who entered Paul's life and was supposedly to act as a father figure to Paul. A man, who was supposed to care for him and look after him. Instead of doing this he ended Paul's life in the most violent way.

'The actions of David Dearlove on 1st October 1968 not only physically killed Paul but also destroyed his memory. He was buried in an unmarked grave the location of which remains unknown and he was not spoken about for many years. However, we now believe as a family that this court case has shown everyone that Paul did live a life and that his memory will never be forgotten.

'Naturally, we are delighted as a family that justice has now been done, even if it did take 47 years to achieve it.

'David Dearlove is now behind bars. This has been a long journey to get to this point and we would like to thank Cleveland Police and those that assisted in bringing the case to court.

'We now hope to move on with our lives, and with justice having been served, hope that Paul can now rest in peace.'

Peter Booth reported the crime to the police after seeing this old photo of his brother

Dearlove was 21 when he moved in with Carol Booth, now deceased, and her three children, and told the jury he liked them but did not love them.

She went on have a baby son by him, born three months after Paul died.

The couple split in 1970 and he never saw Peter again until Mr. Booth faced him in court and told the jury what he saw.

Mr. Booth and his sister Stephanie also told the jury Dearlove had been physically abusive towards them when they were small children.

Paul had a series of injuries of different ages on his body when he died.

A month before, concerns were raised by his nursery about bruises on his body and police and childcare specialists made inquiries but did not take action against the couple.

At the time, Dearlove told the authorities those injuries were caused by Paul pulling a motorbike over in the backyard.

On the night Dearlove killed Paul, he was alone in the room with the child.

He claimed the toddler had collapsed and went with Mrs. Booth in the ambulance to the hospital, returning home sometime later while the toddler remained critically ill.

He heard in a phone call that Paul was dead. An hour and a quarter after hearing the news, he told the jury, he went to bed.

Dearlove showed little emotion when he was cross-examined by Richard Wright QC, prosecuting, about that night.

Mr. Wright asked: 'The child you say you cared about and liked, a baby, had died in your home that night ... it must have been terrible.'

Dearlove said: 'I cannot remember what my feelings were.'

Mr. Wright said: 'Think back, this happy little baby you had been tossing up and down by the fire earlier in the evening, you found him with a fatal injury, and the woman you loved - Carol - had just lost her son. Was that a bit upsetting?'

In graphic evidence, a baby doll was marked up with the different injury sites and shown to the jury.

Home Office pathologist Dr. Mark Egan then hit the doll's head on a hard surface to show how the skull fracture could have been caused.

Dearlove, who had no previous convictions, moved to London after his split with Mrs. Booth and started a new life. He married, had two daughters and is now a grandfather.

After his conviction today, an NSPCC spokesman said: 'This awful crime robbed a defenseless child of his life almost 50 years ago - and Dearlove probably thought he'd long got away with his actions.'

Jurors wept as pathologist hit mannequin against witness box

A baby doll was used as a graphic piece of evidence to convict David Dearlove of murder almost 50 years after the act.

The resuscitation mannequin was marked with a blue pen to show the bruises and burns that were found on toddler Paul Booth at his post-mortem examination in October 1968.

As well as marks on elsewhere on his body, there were bruises on his feet and around his neck and the jury heard these were not the usual places a small child would hurt themselves accidentally in play.

Home Office pathologist Mark Egan used the doll to demonstrated how he thought Paul could have died by swinging the doll by the ankles and banging its head on the surface of the witness box.

Some of the 10 women and two men on the jury wept when they saw the demonstration.

Dr. Egan told Teesside Crown Court he believed it would have taken separate blows to cause the 'z-shaped' skull fracture on the side of Paul's head.

The jury heard expert evidence that the array of injuries on Paul's body indicated they were not accidental but were caused by someone in the house.

Dearlove had told the jury that Carol Booth was a good mother to the children and she did not hurt them.